Multi-channel signals may be reproduced by three or more speakers, for example, 5.1 or 7.1 surround sound channel speakers to develop three-dimensional (3D) effects.
Conventional surround sound systems can produce sounds placed nearly in any direction with respect to a listener positioned in the so called sweet spot of the system. However, conventional 5.1 or 7.1 surround sound systems do not allow for reproducing auditory events that the listener perceives in a close distance to his head. Several other spatial audio technologies like Wave Field Synthesis (WFS) or Higher Order Ambisonics (HOA) systems are able to produce so-called focused sources, which can create a proximity effect using a high number of loudspeakers for concentrating acoustic energy at a determinable position relative to the listener.
Channel-based surround sound reproduction and object-based scene rendering are known in the art. Several surround sound systems exist that reproduce audio with a plurality of loudspeakers placed around a so-called sweet spot. The sweet spot is the place where the listener should be positioned to perceive an optimal spatial impression of the audio content. Most conventional systems of this type are regular 5.1 or 7.1 systems with 5 or 7 loudspeakers positioned on a rectangle, circle or sphere around the listener and a low frequency effect channel. The audio signals for feeding the loudspeakers are either created during the production process by a mixer (e.g. motion picture sound track) or they are generated in real-time, e.g. in interactive gaming scenarios.